L.A. Noire has appeared on some retail sites in Nordic territories, which is apparently scheduled for November 2011.
This would hardly be surprising since Rockstar has released GOTY editions for all of its major titles. Their GOTY editions usually include all of the released DLC. It would also be a real enticement for PC gamers to pick up L.A. Noire, as it is also reasonable to assume that the debut of L.A. Noire on PC would be a GOTY edition with all of the DLC included.
L.A. Noire was released in May for Xbox 360 and PlayStation 3, and a PC version will be coming in Fall 2011.